Hi Brent,
I want to congratulate you on your article! An excellent piece of work
which should be compulsory reading for all serious haskell
programmers :)
My one suggestion would be that you expand on some of the examples;
for example, in the monoid section, you refer to various cool
applications of Monoid, but do not include them in the paper.
Dedicated readers might follow up on your (rather long!) references
list, but many will not, and it is a shame if they miss the elegance
that Monoid permits. I think that if you would inline some of these
examples, the article would be even better :)
Thanks for writing it!
Edsko